Such a device is known from DE 200 19 939 U1. The actuating element of the blocking means is designed as a brake button, which can be moved into an active position for blocking an unrolling motion during actuation by a person by pressing down the brake button. Based on the actuation of the actuating element, a locking element is moved, in addition, into an active position for blocking the unrolling motion. The locking element can come into contact in the active position with one of a plurality of projections along the circumference of the leash roller, so that an unrolling motion is prevented from occurring. The projection has a first flank, with which the locking element comes into contact. This first flank is arranged at right angles to an acute opening angle to a circumferential surface of the leash roller.
The drawback of this is that a great actuation motion is necessary on the part of a person operating the device to actuate the actuating element and/or to reach an active position for the locking element for blocking the unrolling motion of the leash roller. As a result, there is a risk of fatigue, especially of the thumb used to actuate the actuating element in case of repeated activity.
In addition, there is a risk that the locking element would slide over the projections in a position in which it is not pressed or pivoted down sufficiently in the direction of a projection and in case of a pulling load on the leash in the direction of the unrolling motion. Undesired disturbing noises, especially rattling and increased wear occur now. Due to the great actuating motion necessary for the actuating element, there is a large area that is susceptible to the development of disturbing noises between an unactuated position of the actuating element and a fully actuated, especially pressed, position of the actuating element.